JPS6024223A - Method for controlling bending angle with press brake - Google Patents

Abstract

PURPOSE:To complete bending operation in two stages by calculating the theoretical approach distance of a punch and a die, bending a work, calculating the additional approach distance from the detected data on the driving fluid pressure and correcting the bending angle. CONSTITUTION:Various sets of data such as the shapes and sizes V, Q of a punch and die 15, the thickness T of a work W and a desired bending angle A are inputted to a control device contg. a computer which calculates the theoretical approach distance D between the punch and the die and executes the 1st bending stage. The detector detects 97 thereafter the fluid pressure of a fluid pressure driving device 11 driving the punch and die 15 during progression of the above-mentioned stage, corrects and calculates the dynamical strain quantity by the resistance in the structural part of the punch, the die and the press brake and a fluid pressure valve, the elastic characteristics of the work etc. from the detected value, calculates the additional approach distance and executes the correction. The bending operation of the work is thus completed in the two stages and the loss of the time for trial bending and material is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a press brake, and more particularly to a bending angle control method for controlling the bending angle of a workpiece.

Conventionally, in press brakes, in order to bend a plate-like workpiece to a desired bending angle, the workpiece is positioned between a punch and a die, and then trial bending is performed several times to achieve the desired bending angle. The engagement state of the die was being adjusted.

For this reason, a lot of time and materials were consumed before the actual work started, and the work could not be done efficiently.

In addition, in order to achieve the desired bending operation, much depends on the skill and sensitivity of the operator, making it difficult to complete the actual operation in a short period of time.

The present invention has been made for the purpose of solving the above-mentioned disadvantages of the conventional press brake, and preferred embodiments thereof will be described in detail below based on the drawings.

In FIGS. 1 and 2, the press brake 1 has left and right side plates 5, 5 rising from the bottom plate 3 in a C-shape, and both side plates are placed above and in front of the left and right side plates 5, 5 (left side in FIG. 2). A connecting and covering upper apron 7 is fixed, and a punch 9 is attached to the lower end of the upper apron 7.

A lower apron 13 is provided at a lower position corresponding to the upper apron 7, and is driven by a fluid pressure drive device 11 to move up and down.
A die 15 is attached to the upper end.

A workpiece 17 is mounted on the right side plates 5, 5 of No. 1 of the C-shape.
Alternatively, after bending W, a gap 19 is provided so that the work 17 is inserted from the front because it is necessary to take it out in the bending line direction (H direction of the press brake 1).
Also provided is a back nozzle i-gee device 21 for positioning the fold line of the folding line.

Shown at the left end of FIG. 1 is a control device 23 containing a pump coater.

What is shown in FIG. 3 is the control panel 25 of the control device 23, which includes, for example, a power switch 27, a mode selection switch 29, a
Function key 31・Feed rate selection switch 33・
A process data setting key 35 and the like are provided.

The function keys 31 include a process data setting key 31a for setting parameters necessary to define each process (1!J1 work), a process data display key 311 for displaying the contents of the above data settings, and a process data display key 311 for displaying the contents of the above data settings. A process setting key 31c for setting the execution order and an N4 setting key 31 (1) for setting the auxiliary I geometric parameters and correction amount of the workpiece W set above are provided.

Furthermore, prior to continuous operation, a work call key 31e for specifying the work number to be operated and the current position of the L-axis and D-axis are pressed.
;Position speed hemp display key 31 [to display speed and P A KQ constant S= to set various parameters on the system
-314], a PU start key 31h for starting the puncher and punching out necessary data onto a paper tape, and a self-diagnosis key 311 for displaying alarm contents.

Figure 4 shows what can be expressed graphically among the various data input to the control panel. Shoulder radius Rd, - Desired bending angle A to workpiece W, Pan -
1-9 tip radius Rp.

As shown in FIG. 4, in the general press brake 1, with respect to the workpiece W positioned horizontally on the die 15,
The punch 9 and the die 15 come close to each other, and the bending operation is performed between the lower end of the punch 9 and both shoulders of the groove of the die 15.

More specifically, since the bending operation is performed at three points: the tip radius Rp of the punch 9 and the shoulder radius R (I) of the die 15, it is a so-called air bending method in which there is no planar rigid body in contact with the lower surface of the workpiece W. This is the bending work.

Therefore, the lower end of the punch 9 and the stopped state of the die 15, in other words, how close the lower end of the tip rounded portion Rp of the punch 9 should be to the position where it contacts the groove bottom of the die 15 to achieve the desired result. The bending angle can be determined through geometrical and mathematical calculations.

Fig. 4 shows that in order to bend the workpiece W at an angle of 4-A as described above, the tip of the punch 9 must be at a distance of D (hereinafter referred to as the theoretical approach distance) from the position where it hits the bottom of the V-groove. This indicates that it is best to stay away from it.

If the base angle of the V-groove of the die 15 is θ, it is impossible to bend the angle A to be smaller than the angle θ, and the portion adjacent to the rounded end of the punch 9 is the bent workpiece W.
Since it is clear that contact with the upper surface of the punch 9 is not allowed, in this sense the illustration of the punch 9 is omitted in FIG.

Next, FIG. 5 will be explained.

FIG. 5 shows a control mechanism for controlling the raising and lowering operation of the lower apron 13. A lever 39 is provided at the center of the lower apron 13 in the longitudinal direction and can be freely engaged with and detached from a locking piece 37.

This lever 39 is swingable around a shaft 45 provided on a part of a rotatable movable member 43 via a shaft 41 fixed to a frame (not shown) provided on the back side of the lower apron 13.

Further, a lift limit setting valve 47 for the lower apron 13 is attached to the frame (not shown), and its spool 49 is engaged with one end of the lever 39 via a leaf spring 51 fixed to the frame.

As mentioned above, the rotating member 43 is connected to one end of the thread screw 57 via the pin 53 and the link 55, and is connected to one end of the feed screw 57.
is rotatably supported by a case 59 fixed to the frame.

An internal gear 61 is provided at the other end of the feed screw 57, and a clutch gear 63 that approaches and engages the internal gear 61 on a spline shaft and separates and disengages is provided.

A manual handle 65 is attached to the other end of the clutch gear 63, and a shift lever 67 for moving the clutch gear 63 is mounted on the spline shaft described above.
It is no.

A belt 75 is attached between the internal gear 61 attached to the feed screw 57 and a gear V-73 attached to the shaft 71 of a detector 69, such as an encoder, provided in a part of the corresponding case 59. It's a mawashi.

In addition, the above-mentioned detector 69 includes a gear 77, a belt 79,
A shaft 85 of a clutch 83 is connected via a gear 81, and an output shaft 89 of an electric motor 87 attached to a case 59 is further connected to the clutch 83.

A generator 91 for changing the rotational speed of the electric motor 87 is connected to the other end of the shaft of the electric motor 87.

Next, FIG. 6 is a part of a fluid pressure piping diagram related to the fluid pressure drive device 11 that drives the lower apron 7 up and down and the rise limit setting valve 47, and shows a pump device 93 connected to an electric motor. The oil tank 95 and the pressure horn detector 97 raised from the lower apron 13 are shown.

Although not shown, there is wiring from the pressure detector 97 described above to transmit the detected pressure value to the control device 23.

An example of implementing the present invention using the press brake 1 equipped with the control device 23 with a built-in computer as described above will be described step by step as follows.7- First, the workpiece plate thickness T and the desired bending angle A. Tip radius of punch 9 Rp1 V groove shoulder width of die 15 V die shoulder radius R
d, V-groove bottom angle θ, and other shape and dimensions, bending line length, tensile strength of the workpiece, elastic properties of the workpiece, structural parts of the press brake, such as bending reaction due to the C-shape of the left and right side walls. Mechanical factors include the elastic modulus of elastic deformation when the upper apron 7 rises due to force, the error in the theoretical approach distance due to the tip Rp of the punch biting into the workpiece W, and the flow resistance in the spool and piping of the fluid pressure drive device 11. Elements that cause distortion, including experimental formulas, are input from the control panel 25 to the control device.

Next, as a first stage process, the punch 9 and the die 15 are brought close to each other to a value close to the theoretical value.

Since this theoretical approach distance of 1 dD ignores distortions and errors in the portions related to pressurization as described above, the workpiece W does not reach the desired bending angle.

During this first step, the pressure detector 97 of the fluid pressure drive device 11 detects the fluid pressure.

According to experiments, for example, when bending a workpiece W by 90 degrees, the fluid pressure is 10% from 130 degrees to nearly 90 degrees.
Although the extent of this phenomenon is reduced, it is considered that the main cause of this phenomenon is that the punch 9 and the die 15 are distorted and become distant from each other.

7. Based on the detected fluid pressure data, calculate the distortion correction value based on the mechanical data input earlier.7. .

After correction, calculate and implement the additional approach distance as the second step.

The actual bending angle of the workpiece W when the punch 9 and die 15 are brought close to the theoretical approach distance is calculated by detecting the height of the workpiece W at a certain distance from the center of the V-groove of the bent surface. However, the modifications described above are possible.

Thus, in the embodiment of the present invention described in detail above, there is a step of bending the punch and the die to the theoretical approach distance 1111), and a step in which correction values are obtained by actual work using an actual bending workpiece and additionally brought closer. Since the work is completed in two steps, there is no time loss and material consumption associated with several trial bending steps, and there is no need to rely on the skill and intuition of the worker, eliminating the disadvantages of conventional bending methods. I got it.

[Brief explanation of drawings]

Fig. 1 is a front view of a press brake as an embodiment of the present invention, Fig. 2 is a side view of the same as above, Fig. 3 is a front view of the control panel, and Fig. 4 is a detail of the bending of the forceps, punches, and workpieces. cross section,
FIG. 5 is an explanatory diagram of the approach distance setting mechanism, and FIG. 6 is a part of the same hydraulic piping diagram. (Explanation of symbols representing main parts of the drawings) 1... Press brake 9 Punch 11... Fluid pressure drive device 15... Die 23...
Control device 27...Locking piece 47...Upper/surrounding setting valve 97...Pressure detector patent Applicant: Amada Co., Ltd. 11-

Claims (2)

[Claims] (1) In a press brake equipped with a control device with a built-in computer, the theoretical approach between the punch and die can be calculated from various data related to the shape and dimensions of the punch and die, the thickness of the plate-like workpiece, and the desired bending angle. The process of detecting the driving fluid pressure that drives the punch and die during the progress of the culm; and the process of detecting the structural parts of the punch, die, and press brake from the detected values. A method for controlling a bending angle in a press brake, comprising the steps of calculating and correcting mechanical limbs based on resistance of a fluid pressure valve, elastic characteristics of a workpiece, etc. to obtain an additional approach distance. (2) In place of the step of detecting the driving fluid pressure described above, a step of detecting the bending angle from the height of the bending surface of the workpiece is used. The bending angle control method in the described press brake.